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Gelfand–Mazur theorem

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686: 140:. This result was proved first by Stanisław Mazur alone, but it was published in France without a proof, when the author refused the editor's request to shorten his proof. Gelfand (independently) published a proof of the complex case a few years later. 1209: 1311: 575: 944: 411: 125:
The theorem can be strengthened to the claim that there are (up to isomorphism) exactly three real Banach division algebras: the field of reals
238: 966: 401: 949: 722: 971: 1367: 528: 383: 1296: 959: 359: 1189: 1042: 840: 199: 169: 1037: 191: 251: 1194: 340: 231: 1012: 610: 981: 255: 895: 779: 71: 1204: 715: 406: 830: 689: 462: 396: 224: 1341: 1261: 815: 426: 1316: 1214: 1094: 671: 625: 549: 431: 1321: 1184: 1017: 1002: 774: 666: 482: 190:. International Series in Pure and Applied Mathematics. Vol. 8 (Second ed.). New York, NY: 1362: 913: 903: 784: 708: 518: 416: 319: 1276: 1251: 1069: 1058: 769: 615: 391: 1127: 1117: 1112: 820: 646: 590: 554: 872: 353: 349: 1286: 1265: 1179: 1064: 1027: 629: 151: 216: 8: 1089: 825: 595: 533: 247: 95: 1219: 1148: 1079: 923: 885: 620: 487: 33: 1326: 1301: 986: 908: 600: 205: 195: 185: 165: 1331: 1032: 880: 835: 759: 605: 523: 492: 472: 457: 452: 447: 157: 60: 284: 1306: 1291: 1199: 1162: 1158: 1122: 1084: 1022: 1007: 976: 918: 877: 864: 789: 731: 700: 467: 421: 369: 364: 335: 17: 294: 1256: 1235: 1153: 1143: 954: 861: 794: 754: 656: 508: 309: 56: 41: 37: 29: 161: 1356: 661: 585: 314: 299: 289: 209: 1074: 928: 869: 651: 304: 274: 181: 94:
is not invertible. This is a consequence of the complex-analyticity of the
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of any element of a complex Banach algebra is nonempty: for every element
1271: 856: 580: 570: 477: 279: 764: 513: 345: 134: 52: 45: 749: 735: 1336: 1281: 49: 25: 246: 59:, i. e., the only complex Banach algebra that is a 1312:Spectral theory of ordinary differential equations 730: 576:Spectral theory of ordinary differential equations 1210:Schröder–Bernstein theorems for operator algebras 1354: 716: 232: 149: 70:The theorem follows from the fact that the 723: 709: 239: 225: 529:Group algebra of a locally compact group 150:Bonsall, Frank F.; Duncan, John (1973). 1355: 1043:Spectral theory of normal C*-algebras 841:Spectral theory of normal C*-algebras 704: 220: 180: 1038:Spectral theory of compact operators 192:McGraw-Hill Science/Engineering/Math 13: 1190:Cohen–Hewitt factorization theorem 114:1. This gives an isomorphism from 44:in which every nonzero element is 14: 1379: 1195:Extensions of symmetric operators 1013:Positive operator-valued measure 685: 684: 611:Topological quantum field theory 1368:Theorems in functional analysis 1297:Rayleigh–Faber–Krahn inequality 129:, the field of complex numbers 133:, and the division algebra of 1: 1205:Limiting absorption principle 407:Uniform boundedness principle 143: 82:there is some complex number 831:Singular value decomposition 78:of a complex Banach algebra 7: 1262:Hearing the shape of a drum 945:Decomposition of a spectrum 156:. Springer. pp. 71–4. 10: 1384: 850:Special Elements/Operators 550:Invariant subspace problem 1322:Superstrong approximation 1244: 1228: 1185:Banach algebra cohomology 1172: 1136: 1105: 1051: 1018:Projection-valued measure 1003:Borel functional calculus 995: 937: 894: 849: 803: 775:Projection-valued measure 742: 680: 639: 563: 542: 501: 440: 382: 328: 270: 263: 162:10.1007/978-3-642-65669-9 98:function. By assumption, 914:Spectrum of a C*-algebra 785:Spectrum of a C*-algebra 519:Spectrum of a C*-algebra 153:Complete Normed Algebras 1342:Wiener–Khinchin theorem 1277:Kuznetsov trace formula 1252:Almost Mathieu operator 1070:Banach function algebra 1059:Amenable Banach algebra 816:Gelfand–Naimark theorem 770:Noncommutative topology 616:Noncommutative geometry 63:is the complex numbers 1317:Sturm–Liouville theory 1215:Sherman–Takeda theorem 1095:Tomita–Takesaki theory 870:Hermitian/Self-adjoint 821:Gelfand representation 672:Tomita–Takesaki theory 647:Approximation property 591:Calculus of variations 811:Gelfand–Mazur theorem 667:Banach–Mazur distance 630:Generalized functions 22:Gelfand–Mazur theorem 1287:Proto-value function 1266:Dirichlet eigenvalue 1180:Abstract index group 1065:Approximate identity 1028:Rigged Hilbert space 904:Krein–Rutman theorem 750:Involution/*-algebra 412:Kakutani fixed-point 397:Riesz representation 102:1 −  90:1 −  36:which states that a 1090:Von Neumann algebra 826:Polar decomposition 596:Functional calculus 555:Mahler's conjecture 534:Von Neumann algebra 248:Functional analysis 187:Functional Analysis 40:with unit over the 1220:Unbounded operator 1149:Essential spectrum 1128:Schur–Horn theorem 1118:Bauer–Fike theorem 1113:Alon–Boppana bound 1106:Finite-Dimensional 1080:Nuclear C*-algebra 924:Spectral asymmetry 621:Riemann hypothesis 320:Topological vector 1350: 1349: 1327:Transfer operator 1302:Spectral geometry 987:Spectral abscissa 967:Approximate point 909:Normal eigenvalue 698: 697: 601:Integral operator 378: 377: 201:978-0-07-054236-5 171:978-3-642-65671-2 1375: 1332:Transform theory 1052:Special algebras 1033:Spectral theorem 996:Spectral Theorem 836:Spectral theorem 725: 718: 711: 702: 701: 688: 687: 606:Jones polynomial 524:Operator algebra 268: 267: 241: 234: 227: 218: 217: 213: 175: 61:division algebra 1383: 1382: 1378: 1377: 1376: 1374: 1373: 1372: 1363:Banach algebras 1353: 1352: 1351: 1346: 1307:Spectral method 1292:Ramanujan graph 1240: 1224: 1200:Fredholm theory 1168: 1163:Shilov boundary 1159:Structure space 1137:Generalizations 1132: 1123:Numerical range 1101: 1085:Uniform algebra 1047: 1023:Riesz projector 1008:Min-max theorem 991: 977:Direct integral 933: 919:Spectral radius 890: 845: 799: 790:Spectral radius 738: 732:Spectral theory 729: 699: 694: 676: 640:Advanced topics 635: 559: 538: 497: 463:Hilbert–Schmidt 436: 427:Gelfand–Naimark 374: 324: 259: 245: 202: 172: 146: 57:complex numbers 42:complex numbers 34:Stanisław Mazur 18:operator theory 12: 11: 5: 1381: 1371: 1370: 1365: 1348: 1347: 1345: 1344: 1339: 1334: 1329: 1324: 1319: 1314: 1309: 1304: 1299: 1294: 1289: 1284: 1279: 1274: 1269: 1259: 1257:Corona theorem 1254: 1248: 1246: 1242: 1241: 1239: 1238: 1236:Wiener algebra 1232: 1230: 1226: 1225: 1223: 1222: 1217: 1212: 1207: 1202: 1197: 1192: 1187: 1182: 1176: 1174: 1170: 1169: 1167: 1166: 1156: 1154:Pseudospectrum 1151: 1146: 1144:Dirac spectrum 1140: 1138: 1134: 1133: 1131: 1130: 1125: 1120: 1115: 1109: 1107: 1103: 1102: 1100: 1099: 1098: 1097: 1087: 1082: 1077: 1072: 1067: 1061: 1055: 1053: 1049: 1048: 1046: 1045: 1040: 1035: 1030: 1025: 1020: 1015: 1010: 1005: 999: 997: 993: 992: 990: 989: 984: 979: 974: 969: 964: 963: 962: 957: 952: 941: 939: 935: 934: 932: 931: 926: 921: 916: 911: 906: 900: 898: 892: 891: 889: 888: 883: 875: 867: 859: 853: 851: 847: 846: 844: 843: 838: 833: 828: 823: 818: 813: 807: 805: 801: 800: 798: 797: 795:Operator space 792: 787: 782: 777: 772: 767: 762: 757: 755:Banach algebra 752: 746: 744: 743:Basic concepts 740: 739: 728: 727: 720: 713: 705: 696: 695: 693: 692: 681: 678: 677: 675: 674: 669: 664: 659: 657:Choquet theory 654: 649: 643: 641: 637: 636: 634: 633: 623: 618: 613: 608: 603: 598: 593: 588: 583: 578: 573: 567: 565: 561: 560: 558: 557: 552: 546: 544: 540: 539: 537: 536: 531: 526: 521: 516: 511: 509:Banach algebra 505: 503: 499: 498: 496: 495: 490: 485: 480: 475: 470: 465: 460: 455: 450: 444: 442: 438: 437: 435: 434: 432:Banach–Alaoglu 429: 424: 419: 414: 409: 404: 399: 394: 388: 386: 380: 379: 376: 375: 373: 372: 367: 362: 360:Locally convex 357: 343: 338: 332: 330: 326: 325: 323: 322: 317: 312: 307: 302: 297: 292: 287: 282: 277: 271: 265: 261: 260: 244: 243: 236: 229: 221: 215: 214: 200: 177: 176: 170: 145: 142: 112:λ ·  38:Banach algebra 30:Israel Gelfand 9: 6: 4: 3: 2: 1380: 1369: 1366: 1364: 1361: 1360: 1358: 1343: 1340: 1338: 1335: 1333: 1330: 1328: 1325: 1323: 1320: 1318: 1315: 1313: 1310: 1308: 1305: 1303: 1300: 1298: 1295: 1293: 1290: 1288: 1285: 1283: 1280: 1278: 1275: 1273: 1270: 1267: 1263: 1260: 1258: 1255: 1253: 1250: 1249: 1247: 1243: 1237: 1234: 1233: 1231: 1227: 1221: 1218: 1216: 1213: 1211: 1208: 1206: 1203: 1201: 1198: 1196: 1193: 1191: 1188: 1186: 1183: 1181: 1178: 1177: 1175: 1173:Miscellaneous 1171: 1164: 1160: 1157: 1155: 1152: 1150: 1147: 1145: 1142: 1141: 1139: 1135: 1129: 1126: 1124: 1121: 1119: 1116: 1114: 1111: 1110: 1108: 1104: 1096: 1093: 1092: 1091: 1088: 1086: 1083: 1081: 1078: 1076: 1073: 1071: 1068: 1066: 1062: 1060: 1057: 1056: 1054: 1050: 1044: 1041: 1039: 1036: 1034: 1031: 1029: 1026: 1024: 1021: 1019: 1016: 1014: 1011: 1009: 1006: 1004: 1001: 1000: 998: 994: 988: 985: 983: 980: 978: 975: 973: 970: 968: 965: 961: 958: 956: 953: 951: 948: 947: 946: 943: 942: 940: 938:Decomposition 936: 930: 927: 925: 922: 920: 917: 915: 912: 910: 907: 905: 902: 901: 899: 897: 893: 887: 884: 882: 879: 876: 874: 871: 868: 866: 863: 860: 858: 855: 854: 852: 848: 842: 839: 837: 834: 832: 829: 827: 824: 822: 819: 817: 814: 812: 809: 808: 806: 802: 796: 793: 791: 788: 786: 783: 781: 778: 776: 773: 771: 768: 766: 763: 761: 758: 756: 753: 751: 748: 747: 745: 741: 737: 733: 726: 721: 719: 714: 712: 707: 706: 703: 691: 683: 682: 679: 673: 670: 668: 665: 663: 662:Weak topology 660: 658: 655: 653: 650: 648: 645: 644: 642: 638: 631: 627: 624: 622: 619: 617: 614: 612: 609: 607: 604: 602: 599: 597: 594: 592: 589: 587: 586:Index theorem 584: 582: 579: 577: 574: 572: 569: 568: 566: 562: 556: 553: 551: 548: 547: 545: 543:Open problems 541: 535: 532: 530: 527: 525: 522: 520: 517: 515: 512: 510: 507: 506: 504: 500: 494: 491: 489: 486: 484: 481: 479: 476: 474: 471: 469: 466: 464: 461: 459: 456: 454: 451: 449: 446: 445: 443: 439: 433: 430: 428: 425: 423: 420: 418: 415: 413: 410: 408: 405: 403: 400: 398: 395: 393: 390: 389: 387: 385: 381: 371: 368: 366: 363: 361: 358: 355: 351: 347: 344: 342: 339: 337: 334: 333: 331: 327: 321: 318: 316: 313: 311: 308: 306: 303: 301: 298: 296: 293: 291: 288: 286: 283: 281: 278: 276: 273: 272: 269: 266: 262: 257: 253: 249: 242: 237: 235: 230: 228: 223: 222: 219: 211: 207: 203: 197: 193: 189: 188: 183: 182:Rudin, Walter 179: 178: 173: 167: 163: 159: 155: 154: 148: 147: 141: 139: 136: 132: 128: 123: 121: 117: 113: 109: 105: 101: 97: 93: 89: 85: 81: 77: 73: 68: 66: 62: 58: 54: 51: 50:isometrically 47: 43: 39: 35: 31: 27: 23: 19: 1245:Applications 1075:Disk algebra 929:Spectral gap 810: 804:Main results 652:Balanced set 626:Distribution 564:Applications 417:Krein–Milman 402:Closed graph 186: 152: 137: 130: 126: 124: 119: 115: 111: 107: 103: 99: 91: 87: 83: 79: 75: 69: 64: 28:named after 21: 15: 1272:Heat kernel 972:Compression 857:Isospectral 581:Heat kernel 571:Hardy space 478:Trace class 392:Hahn–Banach 354:Topological 135:quaternions 1357:Categories 950:Continuous 765:C*-algebra 760:B*-algebra 514:C*-algebra 329:Properties 144:References 86:such that 53:isomorphic 46:invertible 736:-algebras 488:Unbounded 483:Transpose 441:Operators 370:Separable 365:Reflexive 350:Algebraic 336:Barrelled 96:resolvent 1337:Weyl law 1282:Lax pair 1229:Examples 1063:With an 982:Discrete 960:Residual 896:Spectrum 881:operator 873:operator 865:operator 780:Spectrum 690:Category 502:Algebras 384:Theorems 341:Complete 310:Schwartz 256:glossary 210:21163277 184:(1991). 106:= 0. So 72:spectrum 878:Unitary 493:Unitary 473:Nuclear 458:Compact 453:Bounded 448:Adjoint 422:Min–max 315:Sobolev 300:Nuclear 290:Hilbert 285:Fréchet 250: ( 55:to the 26:theorem 862:Normal 468:Normal 305:Orlicz 295:Hölder 275:Banach 264:Spaces 252:topics 208:  198:  168:  20:, the 955:Point 280:Besov 24:is a 886:Unit 734:and 628:(or 346:Dual 206:OCLC 196:ISBN 166:ISBN 32:and 158:doi 118:to 48:is 16:In 1359:: 254:– 204:. 194:. 164:. 122:. 110:= 67:. 1268:) 1264:( 1165:) 1161:( 724:e 717:t 710:v 632:) 356:) 352:/ 348:( 258:) 240:e 233:t 226:v 212:. 174:. 160:: 138:H 131:C 127:R 120:C 116:A 108:a 104:a 100:λ 92:a 88:λ 84:λ 80:A 76:a 65:C

Index

operator theory
theorem
Israel Gelfand
Stanisław Mazur
Banach algebra
complex numbers
invertible
isometrically
isomorphic
complex numbers
division algebra
spectrum
resolvent
quaternions
Complete Normed Algebras
doi
10.1007/978-3-642-65669-9
ISBN
978-3-642-65671-2
Rudin, Walter
Functional Analysis
McGraw-Hill Science/Engineering/Math
ISBN
978-0-07-054236-5
OCLC
21163277
v
t
e
Functional analysis

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